The present invention relates to a television system with the functions of Teletext that allow the user to store and edit messages to display on the TV screen as desired, and to a method of storing and editing data thereby.
Referring to FIG. 1, a television system with the functions of teletext comprises TV set A and teletext receiving process section B, in which TV set A is provided with an antenna, tuning portion 2 including a tuner and the controller thereof, first u-processor 3, luminance and chrominance signal processor 4, R.G.B. signal switching circuit 5 and CRT 6. Teletext receiving process section B is provided with data sync separating and slicing means 7, teletext signal processor 8, video signal generating means 9, memory 10, program RAM 11, second u-processor 12, programmed ROM 13 for processing teletext signals and signal generating portion 14.
TV set A may be simillar to a conventional TV set with respect to TV signal processing manners, and therefore will not be further described.
Data sync separating and slicing means 7 of teletext receiving process section B separates synchronizing pulses from composite video signals outputted from tuning portion 2, and converts teletext data carried in vertical blanking interval (VBI) of synchronizing signals into digital signals. Teletext signal processor 8 receives composite video synchronizing signals and teletext digital data of data sync separating and slicing means 7, stores data in the form of First-in and First-out (FIFO) into memory under the control of second u-processor 12 as well as controls to be able to store data at program RAM 11 and receives key signals RXD and S.CLOCK of remote control 1 at first u-processor 3 to carry out the program for transferring key signals to second processor 12.
Video signal generating means 9 has a function of automatically refreshing memory 10 referred to as a program RAM, stores video information commanded by second u-processor 12 at memory 10, and converts video information of memory 10 into analog signals so as to display it on the screen of CRT 6 according to internally generated horizontal and vertical synchronizing signals. Memory 10 stores one page of information to currently be displayed on TV screen.
Program RAM 11 stores temporary information (parameters) directly accessed by second u-processor 12. Programmed ROM 13 for processing teletext signals stores programs for controlling teletext signals. Signal generating portion 14 combines on screen display signals (OSD signals) of first u-processor 3 with chrominance signals of video signal generating means 9 so as to apply combined signals to R.G.B. signal switching circuit 5 in TV set A.
Signals from remote control 1 are transmitted to first u-processor 3 that interprets them and then applies them as key signals through communication lines RXD and S.CLOCK to teletext signal processor 8. Teletext signal processor 8 generates interrupt signals with respect to second u-processor 12 when signals from first u-processor 3 are transferred through a data bus thereto.
However, such a conventional TV set with the functions of teletext is limited so that it may selectively display teletext video signals or television broadcast signals on a CRT.